| Description | ABSTRACT: Dopants are a critical way to tune the properties of materials and enable new functionalities, not only for bulk semiconductors but also novel layered 2D materials such as molybdenum sulfide (MoS2). I will discuss our explorations of Ni-doping of MoS2, which can modulate mechanical and electronic properties. We have calculated the structure and energetics of Ni-doped MoS2 to identify the thermodynamic conditions for the formation of different structures. We find that intercalation (insertion of Ni between layers) is most favorable and it causes a large increase in the interlayer interactions, including elastic modulus and exfoliation energy [1-2]. The Raman spectra of different doped structures have distinct features which can be used experimentally to identify the dopant sites, which has been challenging by other techniques [1]. We also study the metastable 1T structure, and find that Ni dopants can lead to a range of reconstructed phases with interesting electronic properties, which can offer a route to experimental synthesis of these phases [3]. Dopants and defects can also host spin states that are appealing for quantum information applications, but accurate calculation of these states has been a major challenge in electronic structure. I will show how our new spin-flip Bethe-Salpeter approach is able to describe singlet and triplet states in the diamond NV- center defect, and is promising for characterizing novel quantum defects in 2D and 3D materials. |
|---|